Spark plug



Dec. 18 1923.`

L. MOREL SPARK PLUG Filed Aug. 17. 1920 umzwr:

CW www @@Qvdgkm Patented Der. 18, 1923.

Louis nonni., or BoULocNnTsUn-snrnn, Farines, nssrcnon To ANTOINE Lucian SCHMITZ, OF IBl()ULOGlUilfSURf.SEINE,

rennen..

Spann PLU@ Application filed August 17, 1920. Serial N0. 404,285.

(GRANTED UNDER THE' PROVISIONS 0F THE ACT OFMARGH; 3, 1921,

To all 107mm t may concern.'

Be it known that 1, Louis Monial., a citizen ot the Republic of France, residing at i3 Seine, inthe Republic of France, have in` vented certain new and useful Improvements in vSpark Plugs (for which 1 have filed applications in France, application tiled July 5, i919, granted April 80, 1920, No. 505,171, and application tiled 1September 19,'- 1919, granted February 8,119.21', No. 22,595; in Germany, application tiled May 22, 1920, granted February 22, 1922, No. 352,203; in Belgium, application` tiled July 2, 1920, granted August 14, 1920, No. 288,4115; ,in Switzerland, application led July 2,` 1920, granted November 16, 1921, No. 91,681;` in. Spain, application filed J uly ed Uctober 9, 1920, No, 74,437; in 1taly,ap plication tiled July 3, 1920, granted September 18, 1922,. No. 54,624; in Great Britain, application tiled July 5, 1920, accepted May 26, 1921, No. 146,824; in Austria, application filed July 9, 1920, granted April 11, 1922, No. 89,316; in Canada, application tiled Jul 21, 1920,:allowed December-17, 1921, No. 220,126), of which the following is a specification.

1n my FrenchPatent No. I195,138 of June 10, 1918, is described an ignition spark plug one ot the particular features of which consists in the fact that the electrode is made in sections within the spark plugin such manner as to provide for the breaking ot the current within the body of the plug.

`The spark plug which is the object ot this invention is based upon the same principle but contains the following improvements:

A. rEhe spark break is not obtained by cutting the electrode, but by adding at a suitable point a flanged ring surrounding, but with a certain amount of play, a conducting portion provided upon the electrode. By this disposition the spark plug may Abe reduced in length if desired and it isno longer necessaryto divide the electrode into two parts, whereby the assembling of the spark plug is simplified and it will have a stronger construction.

B.. The insulation in this spark plug is carried out in certain-cases by means of a sheathing in mica or like material. 1n spite Rue dmuessean Boule ne-sur-Seine 8 1920, grant-,il

44.1 STAT. L., 131s.)

offthe careand the precautions which are takenwhen mountinga mica sheathing upon a'centrall electrode, this sheathing is liable to lose a part of itsv insulating properties underthe action ot the `great heat prevailing invthe case of high power motors. Attempts have been made to obviate this inconvenience by the use or anair draught, but this method can only be otbeneit to those portions ot the sheathing which are situated farthest from the explosion chamber, i. e., which are lessexposed to injury, and this method is therefore insuliicient.

This invention provides a remedy for this inconvenience either bysuppressing the use of mica as an insulating material and replacing` the same Vby porcelain, or by removing the mica, a considerable distancefrom the explosion chamber, whereby the mica shall be no longer liable to lose its insulating properties.

The following description together with the accompanying drawings which are given by way o:- eXample, set forth the nature and the advantages of this invention.

Figs. 1, 2 and?) showin vertical and axial sectionspark plugsrepresenting three ein bodiments of this invention.

As indicated in the drawings, the elec trode a. is imbedded in aisheath of insulating material bit-or instance in mica, which is constituted in thev forni of a cone c with a cylindrical extension CZ; between these two portions c d is disposed a conducting washer constructed together with the electrode a. The male conicalzportion b engages a por-- tion constituting the vfemale cone of a socket f which is screwed upon the cylinder by means of its threaded portion g. The said socket f supports a ring ,t ot insulating inaterial for instance fibre; upon the said ring isndisposed a flanged ring t' ofconducting material, for instance copper. Upon the iianged ring z' and around the cylindrical portion dof 4an insulating sheathing or" the rod aisfdisposed a ring of insulating material,for instance in libre j having disposed thereon a washer lc through which passes the upper part of the electrode a which has a threaded portion al. A nut Z on the threaded portion bears upon a washer m and main tains the electrode a in its sheathing 5,' at

the'upper end of the threaded rod al is screwed a nut forming a cap n to which can be connected a terminal o; a second terminal g2 can be connected to the ring c'.

The various members constituting the spark plug are so assembled-that betweenv starting, inasmuch as the tension is now iiisuliicient for crossing a spark gap. `When the motor is started the current arrives at p, then 4passes into the ring z' and after the break of the current, it passes through the washer c to the lower portion of the electrode a and produces a spark between the head g and the threaded end g. i

The mounting of the current vterminal members Vupon the nut n and the ring 'i can be carried out in any suitable manner, for instance by means of a spring clamp.

The spark plug shown in Fig. 2 comprises the socket of brass or steel screwed into the motor cylinder by means of its screwthread am; the insulating member b3 preferably of porcelain and of special form and the central electrode o0 terminated at its lowerv part by a portion c1 of pure nickel provided with a shoulder 020 and threaded at its upper part c3". As will be observed, the porcelain member Z20 contains a lower portion Z223V which is relatively` thin, an exterior rounded shoulder Z233, an upper shoulder bto'having connected thereto a truncated cone shaped portion Z230. The said porcelain member 6 bears upon the socket a through the medium of its shoulder Z23o with the interposition of an asbestos joint d1". The central electrode 0 is held clamped by the nut e0 and its shoulder 02 bears upon the corresponding portion Z210 of the porcelain member through the intermediary ofV an asbestos joint 0323. The nut eo'is pressed against the upper part of the porcelain member Z2", with interposition of a copper washer fo and a locking washer f1".

The porcelain member Z23 is pressed upon by the grooved nut g3 which is screwed into a corresponding threaded portion L20 of the said socket and which presses upon the porcelain member through the medium of an asbestos joint (33 which is thus held between the shoulder 64, the truncated cone shaped portion Z250 and the nut go.

A second porcelain member ho of cylindrical form is disposed below the nut go, and

projection 071,3.

- plug operates between these two members is disposed the flanged ring k3 provided with a movable collar Z3 containing a lateral screw threaded Y A milled terminal nut a is screwed upon the said projection.

The spark plug isclosed at its upper part by another porcelain member 0 having bearing thereon the assembling nut p0 with the interposition of a fibre washer go and a copper washer Q10; above the said nut is disposed the current terminal cap r.

As will be readily understood, the ignition spark occurs between the end 013 of the central electrode and the perforated disk @30 secured to the socket. Vhen the spark without a current break, the

current arrivesby the terminal cap r3 and passes through the electrode 00 in the usual manner. When the spark plug operates with spark break, the current arrives in the projection m3, passes through the collar Z", the ring 7c3, then crosses the spark gap 83 and proceeds through the electrode rod 0 as before.

The principal advantage of this method of mounting resides in the safety which is thus obtained. In fact, the spark break only possesses a real advantage provided it is properly adjusted, and the present disposition will always operate under good conditions by reason of the arrangement of the flanged ring lo" even should the height of the same be somewhat variable, this not being the case with a device having the spark gap at the end of the rod and with a direct clamping together by nut and joints.

The spark plug shown inFig. 3 also comprises a socket A threaded at A1, internally threaded at A2 and provided `at the lower part with a perforated disk A3, containing also a central electrode C having a shoulder C2 and a threaded portion C3. But in this case, the porcelain member is simply of annular form, and rests at its lower end B3 upon the socket A through the medium of an asbestos vwasher D1. 1

The electrode C is surrounded by a mica cylinder U having two truncated cone shaped portions U1 and U2 and resting upon the shoulder C2 through the medium of an asbestos joint D2. The porcelain member B is held pressed through the intermediary of an asbestos washer D3 by a grooved nut Gr screwing into the threaded portion A2 of the socket', and having the inner portion thereof turned in conical. shape to iit upon the conical portion U2 of the mica cylinder, the latter being pressed by the nut E through the medium of the copper washer F.

The device terminates at the upper part as in the preceding case by the porcelain member H resting upon the washer D4, the flanged ring K which leaves a gap at S for the sparking, the collar L and the upper and lateral current terminals. As will be observed, this arrangement separates the mica from the explosion chamber and it is thus out of danger of deterioration.

The above mentioned spark plugs operate in a perfect manner and never become clogged up, even upon motors having considerable leaks.

It is understood that this invention is not limited to the hereinbe'tore described embodiments nor to the mounting and the na ture ot the various members, and it is particnlariy to be observed that the insulating portions may be constructed of iibre, mica, porcelain or the like.

Having thus' described the nature ot my said invention and the best means I know ot carrying the saine into practical e'ect I claim 1. i-i disinountable spark plugv adapted to operate with or without disruptive discharge, comprising a central continuous electrode extending throughout the whole length of the spark plug, an insulating inember surrounding the lower part of the central electrode, a socket base, means for pressing said insulating member in a gas-tight manner upon the bottom ot said socket base whiie providing for a dismountable disposition, means toi' pressing the lower end ot said electrode within its insulation in a gastiglit manner, while providing for dismountable disposition, a metal ring surrounding portion ot the central electrode which is not covered by said insulating member, means 'tor maintaining said metal ring distanced troni the part of the central electrode which is not surrounded by the insulation, the space between the ring and the part or" the central electrode not covered by insulation constituting the disruptive discharge gap, means tor bringing current to the metal ring for operating the spark plug upon disruptive discharge, and means for bringing current to the end of the central electrode for operating the spark plug without disruptive discharge.

2. i disinountable spark plug adapted to operate u th or without disruptive discharge, comprising a continuous central electrode extending throughout the whole length of the spark plug, an insulating member surrounding the lower part of the central electrode, a socket base, a ring screwing into the screw-threaded end of said socket base and pressing the said insulating member in a gas-tight manner upon the bottom of said socket base, a nut screwing upon said electrode rod and bearing upon the in sulating member surrounding said rod in `order to connect these two elements together in a gas-tight manner, a metal ring surrounding a portion ot the central electrode which is not covered by said insulating meinber, means for maintaining said metal ring.

distanced trom the part o'l' the central electrode which is not surrounded by the insulation, this space between the ring and the uncovered part of the central electrode constituting the disruptive discharge gap, means tor bringing current to the metal ring tor operating the spark plug upon disruptive discharge, and means tor bringing current to the end or the central electrode for operating the spark plug without disruptive discharge.

3. A dismountable spark plug adapted to operate with or without disruptive discharge, comprising a continuous central elec trede of continuous disposition and extending throughout the whole length ot the spark ping, an insulating member surrounding` the lower part of the central electrode, a socket base, a ring screwing into the screw# threaded end ot said socket base in order to maintain said insulating member within said socket base in a gas-tight manner, an insulating sleeve disposed above the said ring screwing into the socket base, a metal ring disposed upon said insulating sleeve, said ring surrounding the upper end ot the electrode, an insulating member mounted upon said metal ring and loosely traversed by the end of said electrode rod, a nut screwing upon the screw-threaded end oi said eiectrode rod whereby said metal ring shall be tightened and held in place between its two insulating members, the space between the insulating ring and the end ot said electrode rod not covered by insulation constituting the space wherein the disruptive spark is produced` a current terminal in contact with said metal ring and a second current terminal provided at the end of the cen tral electrode rod.

ln testimony whereof i atiix my signature.

' LOUIS MOREL. 

